Author: Christophe Theron
Date: 20:18:24 08/18/00
Go up one level in this thread
On August 18, 2000 at 15:54:50, Vincent Diepeveen wrote:
>On August 18, 2000 at 13:50:58, Christophe Theron wrote:
>
>>On August 18, 2000 at 07:15:30, Vincent Diepeveen wrote:
>>
>>>On August 18, 2000 at 02:00:59, Christophe Theron wrote:
>>>
>>>>On August 17, 2000 at 23:16:56, Vincent Diepeveen wrote:
>>>>
>>>>>On August 17, 2000 at 22:23:54, Uri Blass wrote:
>>>>>
>>>>>>On August 17, 2000 at 21:21:46, Vincent Diepeveen wrote:
>>>>>>
>>>>>>>Hello,
>>>>>>>
>>>>>>>A few years ago (about 3) i claimed that searching 18-20 ply was possible
>>>>>>>with huge hashtables, nullmove, a good evaluation function, and
>>>>>>>several billions of nodes.
>>>>>>
>>>>>>searching 18-20 plies with recursive null move pruning is possible and there is
>>>>>>no doubt about it.
>>>>>>
>>>>>>You may miss things because of null move.
>>>>>
>>>>>Are you referring here that i need a bunch of plies more for a few
>>>>>very rare positions where way more as 2 nullmoves are not enough to
>>>>>see the truth? Just like my program won't find that huge mate as
>>>>>posted a bunch of messages below?
>>>>>
>>>>>>>I was considered nuts by half of the RGCC population, because no
>>>>>>>branching factor was capable of being that good, when you would
>>>>>>>search deeper, your branching factor would NOT get under 4.0, that
>>>>>>>was considered impossible by a lot of people even.
>>>>>>>
>>>>>>>Obviously most people following: "i believe that i see in the ads
>>>>>>>or where i see the outputs from", they challenged me. Some went even
>>>>>>>that far and called me nuts, a liar and a frog and many other terms.
>>>>>>
>>>>>>I did not read RGCC but I believe that people called you a liar because you make
>>>>>>the impression that you can see everything in the next 18-20 plies except some
>>>>>>lines that you will look for only 14-16 plies because of null moves when the
>>>>>>fact is that you can miss also lines with 10 plies because you use recursive
>>>>>>null move pruning(I remember that this was my impression when I read your posts
>>>>>>here about 18-20 plies).
>>>>>>
>>>>>>I do not say that using recursive null move is wrong but your 18-20 ply search
>>>>>>can miss 10 plies lines(If your evaluation is good enough these lines are
>>>>>>usually not important but I believe that there are cases when they are
>>>>>>important)
>>>>>
>>>>>This is incredible hard to believe. The number of positions where
>>>>>3 free moves + qsearch will fail. If that fails, then there must
>>>>>be something really wrong in evaluation! It sure can miss things,
>>>>>but the alternative is to search at most 12 ply fullwidth after
>>>>>a full night. Give me 18-20 plies then WITH nullmove please!
>>>>>
>>>>>So a zugzwang or 2 is no problem to detect then. Apart from that, the
>>>>>rare times we see a zugzwang arise in a game, that's usually already
>>>>>seen by my double nullmove.
>>>>>
>>>>>With a material only program proof isn't hard btw for this,
>>>>>as you can take openingsposition where my stupid experiment played
>>>>>1.a3 searching 30 plies.
>>>>>
>>>>>However, the whole discussion 3 years ago,
>>>>>when i cannot remember any person called Uri Blass posting at that time,
>>>>>was not a claim of mine that chess could be solved.
>>>>>
>>>>>In contradiction!!!!!
>>>>>Where Jaap v/d Herik writes in the start of the 80s in "computerchess"
>>>>>the next quote: "when software will search 10-11 ply then no human will
>>>>>be able to ever beat it". I completely have said the opposite,
>>>>>that after a ply or 12 only evaluation matters!
>>>>>
>>>>>Nowadays i would modify that already to 10 ply, noting that in difficult
>>>>>openingspositions the understanding of todays chess programs is still
>>>>>that bad that they need a few ply more to see some consequences there,
>>>>>so still that 12 there as found by De Groot to be the depth where the
>>>>>majority of short term plans are based upon is still valid!
>>>>>
>>>>>I said this partly based upon also experiences of my draughtsprogram
>>>>>which already for years can search easily 25-30 ply after a night, and
>>>>>the only way in which we (marcel monteba and me) could improve the
>>>>>search was by adding knowledge. This draughts program searches fullwidth
>>>>>by the way, as doing nothing is usually very well. I don't need to
>>>>>note that it sees all tactics of world champions within flashes of
>>>>>seconds, where even an average but smart national player can beat it
>>>>>pathetically.
>>>>>
>>>>>My claim was that branching factor above 10 plies was much better as
>>>>>i expected it to be, because of better working of hashtables, and
>>>>>more efficient search by means of a better evaluation which would
>>>>>basically research the same tree over and over again. Basically i
>>>>>claimed that with the number of nodes that Deep Blue searched, one
>>>>>could easily build a much better quality search in software.
>>>>>
>>>>>So what you write here above : "searching 18-20 ply is without doubt
>>>>>possible with nullmove", that's exactly what no one dared to say 3 years
>>>>>ago, and i'm happy you write it here! It proves how opinions have changed,
>>>>>as 3 years ago NO ONE dared to say that, except me.
>>>>>
>>>>>Now i don't want to sound like a profet, but i wanted to raise this
>>>>>discussion a bit to show how fullwidth search has superseded by
>>>>>nullmove driven search, and how these programs have progressed in search
>>>>>the past years and now are dominating the scene, where 10 years ago
>>>>>Genius with a fullwidth search, a few singular extensions, pruning and
>>>>>a clever selective search completely dominated the world of computerchess
>>>>>with tactics, only losing now and then from faster machines.
>>>>
>>>>
>>>>
>>>>In my experience, Genius is one of the most complete program in term of
>>>>knowledge, especially in the endgame. You'll have a hard time if you try to find
>>>>a position that Genius does not understand when other modern programs understand
>>>>it.
>>>
>>>Genius sees tactical a lot indeed, but it's knowledge is really outdated.
>>>It's a slaughter to play against Genius nowadays as it's missing too
>>>much knowledge and it sure isn't good in endgame, the more boring an
>>>endgame is, the bigger the chance it loses it!
>>
>>
>>
>>The only explanation I see is that we do not have the same Genius...
>
>
>Or our rating difference is 2255 points, that's also a possible reason.
>I just missed my IM norm 2 weeks ago. Hope to be IM before 2003.
:) :) :)
It's true I'm lousy at chess, but just because I can't "compute" fast enough. My
positional understanding gets better and better, but that does not help when you
give away all your pieces in a game, like I do.
I have rather chosen to be lousy at chess and to write a good chess program.
I see that you are doing the opposite, and apparently succeed rather well.
Good luck!
Christophe
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